Two-cycle engine



June 15, 1937. ANDREWS 2,083,807

TWO-CYCLE ENGINE Filed June 26, 1935 3 Sheets-Sheet l Wm 1f Z567"; AndreZ05 MOI/"@130.

June 15, 1937.

A. ANDREWS TWO-CYCLE ENGINE Filed Jun 26, 1935 5 Sheets-Sheet 2 & v

anmwtoi U116 15, 1937. A, ANDREWS I 2,083,807

TWO CYCLE ENG INE Filed June 26, 1935 5 Sheets-Sheet 3 amen W01 lm Muses142567; Z f 6 Patented June 15, 1937 UNITED STATES ATENT GFFICEApplication June 26,

4 Claims.

The invention aims primarily to provide a new and improved two-cycleinternal combustion engine of simple inexpensive and Well balancedconstruction, capable of developing great horse power and therefore welladapted for driving land, water or air craft. Two oppositely rotatablecrank shafts are provided, driven by two rows of power pistons, saidcrank shafts serving also as actuating means for pump pistons whichforce explosive gas into the power cylinders to expel the exhaust gasestherefrom and to recharge them, and said crank shafts may well beemployed to drive two propellers in opposite directions tocounterbalance the torque thereof.

With the above and minor objects in view, the invention resides in thenovel subject matter hereinafter described and claimed, descriptionbeing accomplished by reference to the accompanying drawings, wherein:

Fig. 1 is a top plan view.

Fig. 2 is a longitudinal sectional view partly in elevation as indicatedby line 22 of Fig. 1.

Fig. 3 is a vertical transverse sectional view on the irregular line 33of Fig. 1.

A preferred construction has been illustrated and while thisconstruction will be rather specifically described, variations may bemade within the scope of the invention as claimed.

A crank case 5 having a suitable pan 6 carries two rows of powercylinders l and a row of gas-pumping cylinders 8, the cylinders i beingpreferably located similarly to those of a V- type motor and thecylinders 53 being disposed between the two rows of cylinders l. Thecylinders i are preferably formed in two separate blocks 9 having waterjackets ill but the cylinders 8 may be air-cooled, for which purposefins II are shown.

The cylinders l contain power pistons l2 connected by rods 13 with thecranks M of two parallel crank shafts I5 which rotate in oppositedirections. In a motor such as herein disclosed, having eight powercylinders, the cranks M are set 90 apart and the engine is preferablytimed so that the first two cylinders fire first; the next two, second;the third two, third; and the fourth two, last. The pistons l2 act asthe sole valve means for gas admission ports l6 and exhaust gas ports 51which are formed through opposite portions of the side walls of thepower.cylinders 'l.

The gas-pumping cylinders 8 contain gaspumping pistons 18 which areconnected by diverging rods IS with the cranks M of the crank shafts H5.The rods 19 may either connect di- 1935, Serial No. 28,575

rectly with the cranks M or may be pinned at 28 to the power rods [3.Thus, the same cranks which are used in transmitting rotary motion tothe shafts I5 act as actuating means for the pump pistons i8 and byusing the diverging rods it, the pistons l8 have no lateral throw tocreate wear and eventually cause piston slap.

Each pumping cylinder 8 is provided with a gas admission check valve 2|communicating with an intake manifold 22 leading from a suitablecarbureter, and the side wall of each of said cylinders 8 is providedwith two gas discharge ports 23 for communication with the lower ends ofgas discharge passages 24 formed in the pistons i8. Gas-conducting pipes25 lead from the gas discharge ports 23 of the cylinders 8 to the gasadmission ports iii of the power cylinders 1, in such manner that thegas compressed in one cylinder 8 will drive out the exhaust gases fromtwo of the power cylinders l and recharge the latter, the gas compressedin another of the cylinders 8 will similarly scavenge and rechargeanother pair of the power cylinders l, etc.

Fig. 3 illustrates two of the power pistons l2 at the ends of theirpower strokes and illustrates also the piston 13 and cylinder 8 whichserve the power cylinders l of said pistons l2. By the time thesepistons l2 reach the ends of their power strokes, they have opened gasadmission ports I 6 and the gas exhaust ports l1, and piston l8 hasascended and brought the ports 24 in communication with the ports 23.The result is that the gas compressed above the piston I8 (admittedthrough valve 2i on the previous descent of said piston i8) is forcedthrough the passages 24, ports 23, pipes 25 and ports it into thecylinders 1, thereby driving out the spent gases through the exhaustports H and recharging said cylinders 1. When the pistons l2 ascend,this gas is compressed in readiness for firing, effected by conventionalignition means including spark plugs 26. As the power pistons I 2ascend, pump piston l8 descends, drawing in fresh gas into the cylinder8 in readiness for compression.

It will be seen from the foregoing that simple and advantageousconstruction has been provided for carrying out the objects of theinvention.

The engine may be used for driving any selected load but forillustrative purposes, I have shown two oppositely driven propellers 2'!which may be operatively connected with the two crank shafts I 5 in themanner disclosed in my copending application Serial No. 28,574 filedJune 26, 1935.

I claim:

1. In a two-cycle internal combustion engine, two rows of powercylinders, power pistons in said power cylinders,- two oppositelyrotatable crank shafts, rods connecting the pistons of one of said rowsof power cylinders with the cranks of one of said crank shafts, otherrods connecting the pistons of the other row of power cylinders with thecranks of the other crank shaft, and scavenging and charging means forsaid power cylinders including a row of gas-pumping cylinders, pumpingpistons in said gas pumping cylinders, and diverging rods connected tosaid pumping pistons and actuated by the same cranks with which theaforesaid rods are connected, there being two of said diverging rodsconnected with each one of said pumping pistons, one of these rods beingoperatively connected with a crank of one of said crank shafts and theother operatively connected with a corresponding crank of the other ofsaid crank shafts.

2. In a two-cycle internal combustion engine, two rows of powercylinders, power pistons in said power cylinders, two oppositelyrotatable crank shafts, rods connecting the pistons of one of said rowsof power cylinders with the cranks of one of said crank shafts, otherrods connecting the pistons of the other row of power cylinders with thecranks of the other crank shaft, and scavenging and charging means forsaid power cylinders including a row of gas pumping cylinders betweensaid rows of power cylinders, pumping pistons in said gas-pumpingcylinders, and diverging rods connected to said pumping pistons andactuated by the same cranks with which the aforesaid rods are connected,there being two of said diverging rods connected with each one of saidpumping pistons, one of these rods being operatively connected with acrank of one of said crank shafts and the other operatively connectedwith a corresponding crank of the other of said crank shafts. v

3. In a two-cycle internal combustion engine, two rows of powercylinders, each having opposed gas admission and gas exhaust ports,power pistons in said power cylinders acting as valves for said ports,two oppositely rotatable crank shafts, rods connecting the pistons ofone of said rows of power cylinders with the cranks of one of said crankshafts, other rods connecting the pistons of said other row of powercylinders with the cranks of the other crank shaft, a row of gas pumpingcylinders each having a gas admission valve and opposed gas dischargeports, gas pumping pistons in said gas pumping cylinders each having twogas discharge passages for communication with said opposed gas dischargeports of said gas pumping pistons, diverging rods connected to said gaspumping cylinders and actuated by the same cranks with which theaforesaid rods are connected, there being two of said diverging rodsconnected with each one of said pumping pistons, one of these rods beingoperatively connected with a crank of one of said crank shafts and theother operatively connected with a corresponding crank of the other ofsaid crank shafts, and gas conducting passages leading from said gasdischarge ports of said gas pumping cylinders to said gas admissionports of said power cylinders.

4. In a two-cycle internal combustion engine, two rows of powercylinders each having opposed gas admission and gas exhaust ports, powerpistons in said power cylinders acting as valves for said ports, twooppositely rotatable crank shafts, rods connecting the pistons of one ofsaid rows of power cylinders with the cranks of one of said crankshafts, other rods connecting the pistons of said other row of powercylinders with the cranks of the other crank shaft, a row of gas pumpingcylinders between said rows of power cylinders and each having a gasadmission valve and opposed gas discharge ports, gas pumping pistons insaid gas pumping cylinders each having two gas discharge passages forcommunication with said opposed gas discharge ports of said gas pumpingcylinders, diverging rods connected to said gas pumping pistons andactuated by the same cranks with which the aforesaid rods are connected,there being two of said diverging rods connected with each one of saidpumping pistons, one of these rods being operatively connected with acrank of one of said crank shafts and the other operatively connectedwith a corresponding crank of the other of said crank shafts, and gasconducting passages leading from said gas discharge ports of said gaspumping cylinders to said gas admission ports of said power cylinders.

ALBERT ANDREWS.

